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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Copyright (C) 2010 TTPASI, Inc. All Rights Reserved.<a name="line.2"></a>
<FONT color="green">003</FONT>     *<a name="line.3"></a>
<FONT color="green">004</FONT>     * Licensed under the Apache License, Version 2.0 (the "License");<a name="line.4"></a>
<FONT color="green">005</FONT>     * you may not use this file except in compliance with the License.<a name="line.5"></a>
<FONT color="green">006</FONT>     * You may obtain a copy of the License at<a name="line.6"></a>
<FONT color="green">007</FONT>     *<a name="line.7"></a>
<FONT color="green">008</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.8"></a>
<FONT color="green">009</FONT>     *<a name="line.9"></a>
<FONT color="green">010</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.10"></a>
<FONT color="green">011</FONT>     * distributed under the License is distributed on an "AS-IS" BASIS,<a name="line.11"></a>
<FONT color="green">012</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.12"></a>
<FONT color="green">013</FONT>     * See the License for the specific language governing permissions and<a name="line.13"></a>
<FONT color="green">014</FONT>     * limitations under the License.<a name="line.14"></a>
<FONT color="green">015</FONT>     */<a name="line.15"></a>
<FONT color="green">016</FONT>    <a name="line.16"></a>
<FONT color="green">017</FONT>    package ttpasi.jgenere.initial_port;<a name="line.17"></a>
<FONT color="green">018</FONT>    <a name="line.18"></a>
<FONT color="green">019</FONT>    import static ttpasi.jgenere.initial_port.Utils.Aa;<a name="line.19"></a>
<FONT color="green">020</FONT>    import static ttpasi.jgenere.initial_port.Utils.fixAndMakePositive;<a name="line.20"></a>
<FONT color="green">021</FONT>    import static ttpasi.jgenere.initial_port.Utils.isAlpha;<a name="line.21"></a>
<FONT color="green">022</FONT>    import static ttpasi.jgenere.initial_port.Utils.lower;<a name="line.22"></a>
<FONT color="green">023</FONT>    <a name="line.23"></a>
<FONT color="green">024</FONT>    /**<a name="line.24"></a>
<FONT color="green">025</FONT>     * Java port of Caesar cipher from PyGenere v 0.3.  See pygenere.py to learn  <a name="line.25"></a>
<FONT color="green">026</FONT>     * more about the original PyGenere implementation, including author contact <a name="line.26"></a>
<FONT color="green">027</FONT>     * information and licensing and use terms.<a name="line.27"></a>
<FONT color="green">028</FONT>     * &lt;p/&gt;<a name="line.28"></a>
<FONT color="green">029</FONT>     * Caesar objects can encipher and decipher English alphabet text messages.  See <a name="line.29"></a>
<FONT color="green">030</FONT>     * &lt;a target="_blank" href="http://en.wikipedia.org/wiki/Caesar_cipher"&gt;http://en.wikipedia.org/wiki/Caesar_cipher&lt;/a&gt; <a name="line.30"></a>
<FONT color="green">031</FONT>     * for more information on how the Caesar cipher works.<a name="line.31"></a>
<FONT color="green">032</FONT>     * &lt;p/&gt;<a name="line.32"></a>
<FONT color="green">033</FONT>     * Caesar objects are immutable. Calls to the encryption algorithms encipher and <a name="line.33"></a>
<FONT color="green">034</FONT>     * decipher return new Caesar objects with the internal message shifted as <a name="line.34"></a>
<FONT color="green">035</FONT>     * specified.<a name="line.35"></a>
<FONT color="green">036</FONT>     * &lt;p/&gt;<a name="line.36"></a>
<FONT color="green">037</FONT>     * This typical use sequence to encrypt a message<a name="line.37"></a>
<FONT color="green">038</FONT>     * &lt;pre&gt;<a name="line.38"></a>
<FONT color="green">039</FONT>     * String plaintext = "The quick brown fox jumps over the lazy dog.";<a name="line.39"></a>
<FONT color="green">040</FONT>     * Caesar caesar = new Caesar(plaintext);<a name="line.40"></a>
<FONT color="green">041</FONT>     * String ciphertext = caesar.encipher(5).text();<a name="line.41"></a>
<FONT color="green">042</FONT>     * System.out.println(ciphertext);<a name="line.42"></a>
<FONT color="green">043</FONT>     * &lt;/pre&gt;<a name="line.43"></a>
<FONT color="green">044</FONT>     * outputs<a name="line.44"></a>
<FONT color="green">045</FONT>     * &lt;pre&gt;<a name="line.45"></a>
<FONT color="green">046</FONT>     * Ymj vznhp gwtbs ktc ozrux tajw ymj qfed itl.<a name="line.46"></a>
<FONT color="green">047</FONT>     * &lt;/pre&gt;<a name="line.47"></a>
<FONT color="green">048</FONT>     * This typical use sequence to decrypt a message<a name="line.48"></a>
<FONT color="green">049</FONT>     * &lt;pre&gt;<a name="line.49"></a>
<FONT color="green">050</FONT>     * String ciphertext = "Ymj vznhp gwtbs ktc ozrux tajw ymj qfed itl.";<a name="line.50"></a>
<FONT color="green">051</FONT>     * Caesar caesar = new Caesar(ciphertext);<a name="line.51"></a>
<FONT color="green">052</FONT>     * String plaintext = caesar.decipher(5).text();<a name="line.52"></a>
<FONT color="green">053</FONT>     * System.out.println(plaintext);<a name="line.53"></a>
<FONT color="green">054</FONT>     * &lt;/pre&gt;<a name="line.54"></a>
<FONT color="green">055</FONT>     * outputs<a name="line.55"></a>
<FONT color="green">056</FONT>     * &lt;pre&gt;<a name="line.56"></a>
<FONT color="green">057</FONT>     * The quick brown fox jumps over the lazy dog.<a name="line.57"></a>
<FONT color="green">058</FONT>     * &lt;/pre&gt;<a name="line.58"></a>
<FONT color="green">059</FONT>     * See jgenere.initial_port.CaesarEncipherDecipherTest source code for further <a name="line.59"></a>
<FONT color="green">060</FONT>     * example uses. <a name="line.60"></a>
<FONT color="green">061</FONT>     * &lt;p/&gt;<a name="line.61"></a>
<FONT color="green">062</FONT>     * Note: While the cryptography implementations in jgenere.initial_port work <a name="line.62"></a>
<FONT color="green">063</FONT>     * correctly according to the provided test cases, they were not optimized or <a name="line.63"></a>
<FONT color="green">064</FONT>     * otherwise designed to make use of Java language and platform features.  They <a name="line.64"></a>
<FONT color="green">065</FONT>     * are simple ports of the original Python implementation of PyGenere, provided <a name="line.65"></a>
<FONT color="green">066</FONT>     * for academic purposes.  Visit the project web site at <a name="line.66"></a>
<FONT color="green">067</FONT>     * &lt;a target="_blank" href="http://code.google.com/p/jgenere/"&gt;http://code.google.com/p/jgenere/&lt;/a&gt; <a name="line.67"></a>
<FONT color="green">068</FONT>     * for preferred Java-based implementations of these cryptography algorithms.<a name="line.68"></a>
<FONT color="green">069</FONT>     * &lt;p/&gt;<a name="line.69"></a>
<FONT color="green">070</FONT>     * The original PyGenere v 0.3 Caesar code:<a name="line.70"></a>
<FONT color="green">071</FONT>     * &lt;pre&gt;<a name="line.71"></a>
<FONT color="green">072</FONT>     * class Caesar(str):<a name="line.72"></a>
<FONT color="green">073</FONT>     * <a name="line.73"></a>
<FONT color="green">074</FONT>     *   """An implementation of the Caesar cipher."""<a name="line.74"></a>
<FONT color="green">075</FONT>     * <a name="line.75"></a>
<FONT color="green">076</FONT>     *   def encipher(self, shift):<a name="line.76"></a>
<FONT color="green">077</FONT>     *       """Encipher input (plaintext) using the Caesar cipher and return it<a name="line.77"></a>
<FONT color="green">078</FONT>     *          (ciphertext)."""<a name="line.78"></a>
<FONT color="green">079</FONT>     *       ciphertext = []<a name="line.79"></a>
<FONT color="green">080</FONT>     *       for p in self:<a name="line.80"></a>
<FONT color="green">081</FONT>     *           if p.isalpha():<a name="line.81"></a>
<FONT color="green">082</FONT>     *               ciphertext.append(chr((ord(p) - ord('Aa'[int(p.islower())]) +<a name="line.82"></a>
<FONT color="green">083</FONT>     *               shift) % 26 + ord('Aa'[int(p.islower())])))<a name="line.83"></a>
<FONT color="green">084</FONT>     *           else:<a name="line.84"></a>
<FONT color="green">085</FONT>     *               ciphertext.append(p)<a name="line.85"></a>
<FONT color="green">086</FONT>     *       return Caesar(''.join(ciphertext))<a name="line.86"></a>
<FONT color="green">087</FONT>     * <a name="line.87"></a>
<FONT color="green">088</FONT>     *   def decipher(self, shift):<a name="line.88"></a>
<FONT color="green">089</FONT>     *       """Decipher input (ciphertext) using the Caesar cipher and return it<a name="line.89"></a>
<FONT color="green">090</FONT>     *          (plaintext)."""<a name="line.90"></a>
<FONT color="green">091</FONT>     *       return self.encipher(-shift)<a name="line.91"></a>
<FONT color="green">092</FONT>     * &lt;/pre&gt;<a name="line.92"></a>
<FONT color="green">093</FONT>     * <a name="line.93"></a>
<FONT color="green">094</FONT>     * @author  Bruce [com.gmail @ ProgrammerBruce]<a name="line.94"></a>
<FONT color="green">095</FONT>     * @version 2010.1105<a name="line.95"></a>
<FONT color="green">096</FONT>     */<a name="line.96"></a>
<FONT color="green">097</FONT>    public class Caesar<a name="line.97"></a>
<FONT color="green">098</FONT>    {<a name="line.98"></a>
<FONT color="green">099</FONT>      /**<a name="line.99"></a>
<FONT color="green">100</FONT>       * The internal text message to be enciphered or deciphered.<a name="line.100"></a>
<FONT color="green">101</FONT>       */<a name="line.101"></a>
<FONT color="green">102</FONT>      private final String _text;<a name="line.102"></a>
<FONT color="green">103</FONT>    <a name="line.103"></a>
<FONT color="green">104</FONT>      /**<a name="line.104"></a>
<FONT color="green">105</FONT>       * Constructs a new Caesar with a text message to be enciphered or deciphered.<a name="line.105"></a>
<FONT color="green">106</FONT>       * <a name="line.106"></a>
<FONT color="green">107</FONT>       * @param text The text message to encipher or decipher.<a name="line.107"></a>
<FONT color="green">108</FONT>       */<a name="line.108"></a>
<FONT color="green">109</FONT>      public Caesar(String text)<a name="line.109"></a>
<FONT color="green">110</FONT>      {<a name="line.110"></a>
<FONT color="green">111</FONT>        if (text == null)<a name="line.111"></a>
<FONT color="green">112</FONT>        {<a name="line.112"></a>
<FONT color="green">113</FONT>          text = "";<a name="line.113"></a>
<FONT color="green">114</FONT>        }<a name="line.114"></a>
<FONT color="green">115</FONT>        _text = text;<a name="line.115"></a>
<FONT color="green">116</FONT>      }<a name="line.116"></a>
<FONT color="green">117</FONT>    <a name="line.117"></a>
<FONT color="green">118</FONT>      /**<a name="line.118"></a>
<FONT color="green">119</FONT>       * Enciphers (i.e., encrypts) the internal text message, shifted by the amount <a name="line.119"></a>
<FONT color="green">120</FONT>       * specified.<a name="line.120"></a>
<FONT color="green">121</FONT>       * <a name="line.121"></a>
<FONT color="green">122</FONT>       * @param     shift Distance along English alphabet to shift the message.<a name="line.122"></a>
<FONT color="green">123</FONT>       * @return    New Caesar object with the enciphered message.<a name="line.123"></a>
<FONT color="green">124</FONT>       */<a name="line.124"></a>
<FONT color="green">125</FONT>    //def encipher(self, shift):<a name="line.125"></a>
<FONT color="green">126</FONT>      public Caesar encipher(int shift)<a name="line.126"></a>
<FONT color="green">127</FONT>      {<a name="line.127"></a>
<FONT color="green">128</FONT>        shift = fixAndMakePositive(shift);<a name="line.128"></a>
<FONT color="green">129</FONT>    //  ciphertext = []<a name="line.129"></a>
<FONT color="green">130</FONT>        StringBuilder ciphertext = new StringBuilder(_text.length());<a name="line.130"></a>
<FONT color="green">131</FONT>        char[] text = _text.toCharArray();<a name="line.131"></a>
<FONT color="green">132</FONT>    //  for p in self:<a name="line.132"></a>
<FONT color="green">133</FONT>        for (char p : text)<a name="line.133"></a>
<FONT color="green">134</FONT>        {<a name="line.134"></a>
<FONT color="green">135</FONT>    //    if p.isalpha():<a name="line.135"></a>
<FONT color="green">136</FONT>          if (isAlpha(p))<a name="line.136"></a>
<FONT color="green">137</FONT>          {<a name="line.137"></a>
<FONT color="green">138</FONT>    //      ciphertext.append(<a name="line.138"></a>
<FONT color="green">139</FONT>            ciphertext.append(<a name="line.139"></a>
<FONT color="green">140</FONT>    //             chr(<a name="line.140"></a>
<FONT color="green">141</FONT>                (char)(<a name="line.141"></a>
<FONT color="green">142</FONT>    //            (  ord(p) -   ord('Aa'[  int( p.islower( ))]) + shift)<a name="line.142"></a>
<FONT color="green">143</FONT>                  ((int)(p) - (int)( Aa [(int)(     lower(p))]) + shift)<a name="line.143"></a>
<FONT color="green">144</FONT>    //            % 26 +   ord('Aa'[  int( p.islower( ))])<a name="line.144"></a>
<FONT color="green">145</FONT>                  % 26 + (int)( Aa [(int)(     lower(p))])<a name="line.145"></a>
<FONT color="green">146</FONT>    //          )<a name="line.146"></a>
<FONT color="green">147</FONT>                )<a name="line.147"></a>
<FONT color="green">148</FONT>    //      )<a name="line.148"></a>
<FONT color="green">149</FONT>            );<a name="line.149"></a>
<FONT color="green">150</FONT>          }<a name="line.150"></a>
<FONT color="green">151</FONT>    //    else:<a name="line.151"></a>
<FONT color="green">152</FONT>          else<a name="line.152"></a>
<FONT color="green">153</FONT>          {<a name="line.153"></a>
<FONT color="green">154</FONT>    //      ciphertext.append(p)<a name="line.154"></a>
<FONT color="green">155</FONT>            ciphertext.append(p);<a name="line.155"></a>
<FONT color="green">156</FONT>          }<a name="line.156"></a>
<FONT color="green">157</FONT>        }<a name="line.157"></a>
<FONT color="green">158</FONT>    //  return Caesar(''.join(ciphertext))<a name="line.158"></a>
<FONT color="green">159</FONT>        return new Caesar(ciphertext.toString());<a name="line.159"></a>
<FONT color="green">160</FONT>      }<a name="line.160"></a>
<FONT color="green">161</FONT>    <a name="line.161"></a>
<FONT color="green">162</FONT>      /**<a name="line.162"></a>
<FONT color="green">163</FONT>       * Deciphers (i.e., decrypts) the internal text message, backshifted (i.e., <a name="line.163"></a>
<FONT color="green">164</FONT>       * backwards shifted) by the amount specified.<a name="line.164"></a>
<FONT color="green">165</FONT>       * <a name="line.165"></a>
<FONT color="green">166</FONT>       * @param     backshift Distance along English alphabet to backwards shift the <a name="line.166"></a>
<FONT color="green">167</FONT>       *            message.<a name="line.167"></a>
<FONT color="green">168</FONT>       * @return    New Caesar object with the deciphered message.<a name="line.168"></a>
<FONT color="green">169</FONT>       */<a name="line.169"></a>
<FONT color="green">170</FONT>    //def decipher(self, shift):<a name="line.170"></a>
<FONT color="green">171</FONT>      public Caesar decipher(int backshift)<a name="line.171"></a>
<FONT color="green">172</FONT>      {<a name="line.172"></a>
<FONT color="green">173</FONT>        backshift = fixAndMakePositive(backshift);<a name="line.173"></a>
<FONT color="green">174</FONT>    //  return self.encipher(-shift)<a name="line.174"></a>
<FONT color="green">175</FONT>        return encipher(-1 * backshift);<a name="line.175"></a>
<FONT color="green">176</FONT>      }<a name="line.176"></a>
<FONT color="green">177</FONT>    <a name="line.177"></a>
<FONT color="green">178</FONT>      /**<a name="line.178"></a>
<FONT color="green">179</FONT>       * Retrieves the internal English alphabet text message.<a name="line.179"></a>
<FONT color="green">180</FONT>       * <a name="line.180"></a>
<FONT color="green">181</FONT>       * @return The internal English alphabet text message.<a name="line.181"></a>
<FONT color="green">182</FONT>       */<a name="line.182"></a>
<FONT color="green">183</FONT>      public String text()<a name="line.183"></a>
<FONT color="green">184</FONT>      {<a name="line.184"></a>
<FONT color="green">185</FONT>        return _text;<a name="line.185"></a>
<FONT color="green">186</FONT>      }<a name="line.186"></a>
<FONT color="green">187</FONT>    <a name="line.187"></a>
<FONT color="green">188</FONT>      /**<a name="line.188"></a>
<FONT color="green">189</FONT>       * Retrieves the internal English alphabet text message.  Same behavior as <a name="line.189"></a>
<FONT color="green">190</FONT>       * {@link #text()}.<a name="line.190"></a>
<FONT color="green">191</FONT>       * <a name="line.191"></a>
<FONT color="green">192</FONT>       * @return The internal English alphabet text message.<a name="line.192"></a>
<FONT color="green">193</FONT>       */<a name="line.193"></a>
<FONT color="green">194</FONT>      @Override<a name="line.194"></a>
<FONT color="green">195</FONT>      public String toString()<a name="line.195"></a>
<FONT color="green">196</FONT>      {<a name="line.196"></a>
<FONT color="green">197</FONT>        return _text;<a name="line.197"></a>
<FONT color="green">198</FONT>      }<a name="line.198"></a>
<FONT color="green">199</FONT>    }<a name="line.199"></a>




























































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